Do you know about "Chromodulin"?

It is Low-molecular-weight chromium-binding substance (LMWCr)

It is an oligopeptide that seems to transport chromium in the body.

 It consists of four amino acid residues; aspartate, cysteine, glutamate, and glycine, bonded with four (Cr3+) centers.

 It interacts with the insulin receptor and has been confused with glucose tolerance factor.